One charge of culpable homicide that Duduzane Zuma was facing has been withdrawn. 

The case against former president Jacob Zuma's son commenced in the Randburg Magistrate's Court on Tuesday.

Zuma was facing two charges of culpable homicide and a count of negligent driving relating to a car crash on February 1, 2014, on the M1 highway in Gauteng.

On the day, he was driving his Porsche when it rear-ended a minibus taxi, resulting in the death of Zimbabwean national, Phumzile Dube.

The state decided to withdraw the second charge after it had been established that Nanki Jeanette Mashaba, a passenger in the taxi that was rear-ended by Zuma's Porsche, had a pre-existing condition that caused her death in hospital weeks following the incident.

The National Prosecuting Authority had previously declined to prosecute Zuma, but changed its mind after lobby group AfriForum asked to privately prosecute him.

The trial continues.